A 9-year-old male with a limp and a rash
A 9-year-old male presents to your clinic with a limp and a rash. The history of the chief complaint began with some vague low back and posterior left knee pain after baseball practice about a week earlier. Two days later, his left knee pain was aggravated, radiating to his left hip while jumping on a trampoline. The next day, he noted a rash on his left thigh; beginning as a small patch of erythema that quickly spread with the development of some fluid-filled lesions. Soon it was noted that there were numerous, discrete lesions on his back, chest and face. He denies having any fever nor any other complaints during this time.
His past medical history is that of a previously healthy male with recurrent otitis media requiring pressure equalization tubes when he was 18 months of age. The rest is unremarkable. His immunizations are up to date, except for the second dose of varicella vaccine. He has had no recent travel but did camp out at a local lake in a cabin, but he reports no tick or other insect bites. His animal exposure is only the family dog and cat. There are no known sick contacts.
Examination revealed normal vital signs and a normal-appearing 9-year-old male. He has a painful, vesicular rash that is predominately on his left thigh, with a patch on the left buttock, one lesion on the right buttock, scattered lesions below the knee, back, chest and two lesions on his face (Figures 1-6). Palpation of the abdomen produced pain in the left lower quadrant due to stretching of the skin. The rest of his exam was normal.
What’s Your Diagnosis?
C.Pityriasis lichenoides et varioliformis acuta (PLEVA)
D.Herpes zoster with cutaneous dissemination
A case such as this can be very confusing, but this patient turned out to have multidermatomal zoster with cutaneous dissemination (D). The appearance of the lesions fit along with the associated neurologic pain in the area of most involvement and supported by a positive varicella zoster polymerase chain reaction (PCR) taken from one of the representative lesions (Figure 7). The herpes simplex PCR was negative.
You might ask, “Why was that done?” The answer is that I was taught many years ago by the preeminent varicella expert, Phil Brunell, MD, that you cannot always tell by looking whether one of these vesicular rashes is due to varicella or herpes simplex, as there can be much overlap in appearances. If it is important to know, supporting lab tests are needed to be sure.
Nowadays, PCR is the way most of us confirm these infections. The fact that this patient had cutaneous dissemination probably means that he had some viremia associated with the rash. This is fairly uncommon and might raise the question of an immune deficiency. Therefore, he underwent an immune screen to be sure, which was normal. He was treated with high-dose acyclovir (80 mg/kg divided four times per day) and gabapentin (250 mg twice daily) for the neurologic pain. When I saw him back 4 days later, his rash was crusting with no new vesicles and much less pain. In an adolescent, one could choose to use valacyclovir at a dose of 1 g three times daily for 7 days instead of acyclovir.
The typical lesions of varicella can be seen in Figure 8 (courtesy of Michael W. Cater, MD, of Tustin, Calif.), showing the simultaneous appearance of lesions at various stages of development, with a generalized distribution. Also, varicella is not known for causing so much neuralgia as zoster.
Eczema herpeticum is, by definition, a disease in those with damaged skin; eczema, atopic dermatitis or other conditions that leave the skin broken. Therefore, it is fairly easy to rule out if the patient has no underlying skin disorder. The lesions can look the same as any other herpes virus lesions, except they are clustered in areas of damaged skin, as shown in Figures 9 and 10. Severe cases should be treated in a hospital setting at first to be sure it is not progressive, but once crusting begins and no new vesicles are seen, the patient can usually be sent home on oral therapy with close follow-up. I would recommend using the same dose of acyclovir for eczema herpeticum as for zoster until clear improvement is seen. Because herpes simplex infections tend to be recurrent, it is important to reinforce the need for good skin care to prevent this from happening again.
PLEVA is a form of parapsoriasis and not an infectious disease at all. However, it is often initially thought to be a prolonged case of varicella because of the distribution and similarity of lesion appearance from a distance (Figure 11). But, if one looks close, there are no true vesicles but rather papular lesions that may have a thin scale over the top (Figure 12), giving the appearance of a vesicle (a pseudovesicle). I just made that word up, but feel free to use it.
These lesions can occur in crops similar to varicella, only without the vesicle. Many experts do not recommend any specific treatment, as nothing works predictably. If treatment is desired, I refer to a dermatologist. They tend to use UVB phototherapy as the treatment of choice. The rash will often wax and wane for a few months and then resolve, but sometimes the rash may last for years; another reason to get them into a dermatologist sooner than later.
I would like to thank Robert E. Burke, MD, PhD, Vice Chair and Medical Director of the Division of Community General Pediatrics at Children’s Hospital at Scott & White, in Temple, Texas, for contributing this case. If you have an interesting case with a good picture, and you want to see it appear in this column, just let me know at: email@example.com.
Halloween is almost here. Some of my favorite childhood memories are of my friends and I going around the neighborhood in costumes. I think things are a bit more dangerous now than when I was a child. So this may be a good time to educate parents on some common sense advice. I recommend the AAP Halloween Safety Tips Handout, which can be found at the following site and printed out for your waiting room and exam rooms: nwww.aap.org/advocacy/releases/octhalloween.cfm.
James H. Brien, DO, is Vice Chair for Education at The Children’s Hospital at Scott and White and is the Associate Professor of Pediatrics at Texas A&M University, College of Medicine, Temple, Texas. email: firstname.lastname@example.org. Disclosure: Dr. Brien reports no relevant financial disclosures.
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